Electric field time-grating linear displacement sensors based on single row multilayer structure

Abstract

An electric field type time-grating linear displacement sensor based on a single row multilayer structure, including a moving ruler and a fixed ruler. The moving ruler having a row of induced electrodes and the fixed ruler having a row of excitation electrodes.

Description

RELATED APPLICATIONS[0001]This application is a continuation of copending International Application No.: PCT / CN2014 / 083125, filed Jul. 28, 2014, which is in incorporated herein by reference in its entirety, and additionally claims priority to Chinese Application No.: 201410102437.6, filed Mar. 19, 2014, which is also incorporated herein by reference in its entirety.TECHNICAL FIELD[0002]The present invention relates to sensors for precision linear displacement measurement.BACKGROUND ART[0003]In the technical fields of precision linear displacement measurement, in recent years, a new type of time-grating sensor has been developed in China. This time-grating sensor uses a clock pulse as the reference for displacement measurements. And based on the foregoing, a time-grating linear displacement sensor based on alternating electric field has been further developed. The patent application document for this sensor has been published on Dec. 21, 2011 with its Title of Invention as “Time-grat...

AI Technical Summary

Benefits of technology

The present invention provides an electric field type time-grating linear displacement sensor based on a single row multilayer structure. It solves the problems of interference between signals of the two rows of electrodes and inconsistency between the two rows of electrodes resulting from production or installation. It is able to directly obtain the traveling wave signal based on electric field coupling mechanism without an adding circuit, reducing measurement errors and simplifying system structure. The moving ruler electrodes have a double sinusoidal shape formed by two vertically symmetrical sinusoidal shapes connected via a rectangular lead, which can completely cover the facing four excitation signal leads of the fixed ruler electrodes. The sensor has the advantages of low power consumption, high precision, achieving displacement measurement with nanometer precision, simple structure, low requirements for mechanical installation accuracy, and high stability in industrial applications.

Problems solved by technology

However, it has been noted that the two rows of electrode signals may interfere with each other, which may lead to an increase of measurement errors, and thus hinder further improvements in its measurement accuracy.

On the other hand, concerning its manufacturing process, it is difficult to ensure a consistency between the two rows of electrodes; In addition, concerning its installation, it is difficult to ensure consistent electric field coupling strengths between the two rows of electrodes as well.

As a result, the foregoing issues may result in an inconsistency in amplitude of the generated two channels of standing wave signals, which will lead to measurement errors and thus compromise its applications in industrial field.

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